'I Want to Be Seen as Male'

Last year, Barbara Walters spoke with the families of three transgender children who agreed to share their stories. Now, one year later, "20/20" has reached out to the families again to learn what's happened since the original "20/20" episode aired. All three families said that the story helped change their world for the better. Advocacy groups also report a significant surge in young transgenders coming out. Read below to find out more about Jeremy, formerly known as Rebecca.

On Sept. 19, 2004, 14-year-old Rebecca gave a startling letter to her mother, Betsy.

"This is one of those stream of consciousness things that I write in the wee hours of the morning when I'm tired and unable to sleep. I was probably crying when I wrote it, but don't think that the tears blurring my eyes were blurring my judgment as well," Rebecca wrote.

"What am I? I ask myself this all the time. Right now what I believe myself to be is an FTM, or a female-to-male transsexual. A boy in a girl's body. What I want is for you to understand, and let me transition into the boy I really am."

The startling admission left Betsy shocked and bewildered.

"It was an out of body experience," she said. (The family's last name is not being used to protect their privacy.)

For Rebecca, the letter was the culmination of years of anguish over feelings that she had been born into the wrong body. She signed it, "Love, your son," -- a reflection of her deeply held conviction that she was a boy. (Click here to read the full letter).

"I can't quite explain it. It was just a feeling of being not quite in my body," Rebecca said. "When I was in kindergarten, I would tell people that when I grew up I wanted to be a boy. I didn't want to be an astronaut or a teacher. I wanted to be a boy."

'It Didn't Really Feel Like My Body'

Rebecca's parents, however, saw no signs that something was amiss with their youngest child. Raising their family in Los Angeles, the couple worked hard to make their two daughters, Rebecca and Anna, feel that they could do everything that boys could do.

So when Rebecca wanted to play with trucks with other boys, Betsy and her husband weren't troubled.

"I think I must honestly say that I was pretty oblivious to that," said Rebecca's father, Peter.

But it was excruciatingly clear to Rebecca -- even more so when she hit puberty. She felt awkward and uncomfortable when her breasts began to grow. Menstruation, which for most girls is a celebrated right of womanhood, served only to further alienate Rebecca from her own body.

"It didn't really feel like my body, or like this was my life-changing moment. It just seemed like this weird thing that was happening."

Confused, Rebecca went looking for answers, and in the seventh grade, she found them on the Internet. She finally had a word to describe what she was: transgender. She even found other children who struggled with the same feelings she did.

Sharing the Secret

Rebecca had found clarity, but she kept the knowledge of what she was hidden for two more years. Finally, when she was 14 years old, Rebecca told her secret to her sister, Anna, via e-mail.

"I wrote back the same day saying, 'You know, I don't get it yet, but I love you with all my heart. You are my favorite person in the world, and absolutely, whatever you need,'" Anna said.

Anna and Rebecca had always been close. With her sister's support, Rebecca wrote her coming-out letter and gave it to her mother. Despite her initial shock, Betsy kept her composure, and even had the wherewithal to ask whether Rebecca had a new name. She was prepared. Rebecca became Jeremy.

"I didn't see her crying the day I came out," Jeremy said. "She held it in, which was kind of what I needed then. I needed to know that she still loved me. And that this wasn't going to bring her to tears."

Jeremy didn't come out to his father right away, fearful of how he would react. But Peter found out anyway just a few weeks later. While working on his computer, he discovered letters Rebecca wrote about wanting to be a boy.

"I think I just kind of withdrew into some silence because I realized that anger wasn't the correct response," Peter said. "I mean, this had to be accepted somehow."

Becoming Jeremy

Jeremy began to transition into a boy almost immediately after coming out to his parents. He got his hair cut short. He asked his parents to stop referring to him as a she. He bought all his clothes, down to the socks and underwear, from the boys' department. He also began to wear a binder, a Lycra vest that painfully flattened his breasts.

Finally, in the ninth grade, Jeremy came out to his school during an assembly in front of teachers and friends. Going to a progressive school, Jeremy was generally accepted by his classmates.

"The boys at my school did a sort of funny, almost initiation, in which they asked me about which girls that we knew in common I thought were really attractive. It was like they were trying to kind of feel me out," Jeremy said. "It was actually kind of amusing."

Although Jeremy's parents allowed him to use a male name and dress like a boy, in the back of their minds, Peter and Betsy still hoped that their daughter Rebecca would eventually return. They put Jeremy in therapy, hoping that their child was just going through an adolescent phase.

"I did go through a period of hoping that it would wash away. Disappear," Peter said.

"What I really wanted was for the therapist to help Jeremy work through any body issues that might be within the scope of, you know, what normal adolescent girls go through," Betsy said.

'I Want to Be Seen as Male'

As the months wore on, however, it became clear that Jeremy was experiencing something far more serious. He wanted to go beyond merely altering his outward appearance. He wanted to physically change his body as well.

Jeremy insisted on taking the male hormone testosterone, but his parents thought he was too young. They weren't ready to let go of Rebecca completely.

"That was probably the darkest of all of the times that we went through. The many, many talks that we had. And he said to me, 'Mom, you still don't see me as male.' He had been binding, and dressing as a boy, and had a boy's haircut for a full year," Betsy said. "I admitted it. It was true."

"That was hard to hear," Jeremy said. "I knew that they saw me as a transgendered child, but not as a male child. And, the thing is, that I don't really want to be seen as trans. I want to be seen as male."

Without the testosterone, Jeremy felt trapped in a life between genders. He became anxious that his body would never be whole.

'Definitely Ready'

Betsy and Peter ultimately chose to let Jeremy fully transition. In 2006, Peter took Jeremy, 16, to a doctor for his first shot of testosterone.

"Jeremy was a clear-cut case. He came in completely ready. He was definitely ready," said Jo Olson, Jeremy's doctor.

"When you start giving someone hormones of the opposite gender, they go through a puberty. That's exactly what they go through," said Olson, an adolescent medicine specialist at Children's Hospital Los Angeles. "We are trying to get male patterned hair -- so beard, mustache, a little bit more body hair. We are aiming for a deepening of the voice."

"I'm very grateful to have had that experience, to be just a teenaged boy. And now I'm sort of on the same level as the guys I know who are biologically male," Jeremy said. "I'm not stunted anymore."

Last year, Jeremy was a typical high school senior. His name was legally changed after his 16th birthday. He received good grades at school, is accepted by his peers, passes as a boy and looks forward to college enrolled as a male. And like many young men his age, he worries about dating -- other men.

"I could have been a straight woman. But then I would have been someone's girlfriend. And that's … that's not right. What I want to be is someone's boyfriend. That's what feels right," Jeremy said.

Gender and Sexuality

It's not unusual for transgender people to identify as gay. That's because your gender doesn't really determine your romantic attractions, according to Olson.

"There is a big difference between sexuality, or who you're sexually attracted to, and what gender you identify with," she said.

Although surgery is expensive and not covered by insurance, Jeremy, now 18, decided to undergo procedures to remove his breasts. He also attended his senior prom and heads off to college this fall as an honors student. Surgery below the waist -- to create an artificial penis -- is not an option, he says, because the results are often disappointing.

"The surgery for male-to-female transsexuals is a lot better and more realistic than the female-to-male [process]," he said. "It's depressing. Part of me wants to say that it's not fair that I have to stay this way, and that nothing can be done about it. I'm a big believer in the power of medicine to heal. I can't be helped, and that's frustrating."

Betsy and Peter say they will stand behind him. They've accepted that their daughter is now their son, even if a small part of them still wonders whether Rebecca might come back.

"There are times when I can still hold that over myself," Betsy said. "And that was the thing that I think kept me from fully accepting Jeremy. But I've learned so much from our child. You can't predict the future. And you can't control it."

Jeremy has no regrets. Asked what he saw when he looked at pictures of Rebecca, Jeremy said, "I just see someone whose eyes aren't really smiling."

"I'm so much happier than I was before I came out and transitioned. The feeling of wrongness is gone," he said. "I feel for the first time in my life as though I am in the right body. I feel like, the world sees me as I see myself."

The TransKids Purple Rainbow Foundation funds research and educates the public about transgender issues. Please CLICK HERE to visit their Web site.